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From: djh@osc.edu (David Heisterberg)
Newsgroups: comp.arch
Subject: Re: Extremely Fast Filesystems
Message-ID: <780@illini.osc.edu>
Date: 9 Aug 90 14:53:21 GMT
References: <5539@darkstar.ucsc.edu> <13285@yunexus.YorkU.CA> <30728@super.ORG> <13667@cbmvax.commodore.com>
Organization: Ohio Supercomputer Center, Columbus, OH, USA
Lines: 19

In article <13667@cbmvax.commodore.com>, jesup@cbmvax.commodore.com (Randell Jesup) writes:
> 	I submit that your situation is something of an unusual case, and is
> likely to remain unusual for at least a decade, perhaps 2.  Few machines
> (percentage-wise) even have 4 GB of storage, let alone files larger that 4GB
> (I've never even seen a file larger than 100MB, even on mainframes).

Hang around with some quantum chemists sometime.  Files larger than 1GB are
routine.  In recent years so-called direct SCF methods have become popular
(again?) because the study of large molecules results in enormous files for
the two-electron integrals.  The direct methods simply recalculate the
integrals whenever needed.  This is ok for simple SCF calculations, and
Gaussian 90 will have direct MP2, but direct CI and CC is going to be
tough.  Realistic calculations could benefit from address spaces (and real
memory) of 16 GB or more - there are folks who could use that capability
right now.
-- 
David J. Heisterberg		djh@osc.edu		And you all know
The Ohio Supercomputer Center	djh@ohstpy.bitnet	security Is mortals'
Columbus, Ohio  43212		ohstpy::djh		chiefest enemy.